Based on the Datadog Postgres integration documentation, there are a variety of different metrics recorded by the Datadog agent. However, only some of these are available in Aiven for PostgreSQL services.
Currently, Aiven for PostgreSQL reports server and database-level metrics, but not table (or relation) or statement-level metrics. These granular metrics require additional work to be included as options in your Datadog service integration. As such, they are not available for customers at this time.
If you want to be notified when these table-level metrics are configurable for customers, please reach out to support at email@example.com.